This is a dual width, full height card that requires 2 six pin PCIe external power connections and a minimum 500W power supply. Dell says that there are 2 or 3 PCIe slots available depending on the original configuration with only one slot being full height, and 3/4 length, if the server is configured for 2 PCIe slots. If it is configured for 3 PCIe slots then all the slots are half height, half length.

What remains to be determined, I suppose, is whether one of these GTX 980 cards is, for any reason, somehow incompatible with the R620 motherboard, or whether there is just not enough space in the 1u chassis to accommodate... any ideas?

I would check to see if the PCI slots are express x16. I am pretty sure a 1 U rack is not going to be able to accommodate this type of PCI card. The 620 is just going to be too small to fit that in there since it is optimized for smaller slotted cards. If you had a 720 or 730, then maybe since they have more room for GPU K cards.

I don't see how a large card would fit. The Quadros listed as compatible are much smaller; the K600 is half-height, and not really all that much larger than an iPhone. Plus they don't require extra power connections.

I don't see any reason any card that fits wouldn't work in the R620, the ones listed are just what Dell tested (and likely what they'll sell you). Similarly, as long as their are drivers, there's no reason Server 2012 R2 would be an issue with any Nvidia card.

We looked at VDI for our CAD users recently and we needed the 730's because the 630s did not have enough space to support the graphics pieces. These were specialized cards that could be carved up per virtual instance and not high end gaming processers like the 980, but I imagine space is still going to be limiting. I am not sure you could run two cards in parallel (SLI) on the server even if they fit.

I currently have a 620 in our rack and I am certain that 2 980s couldn't fit let alone one.

This is a dual width, full height card that requires 2 six pin PCIe external power connections and a minimum 500W power supply. Dell says that there are 2 or 3 PCIe slots available depending on the original configuration with only one slot being full height, and 3/4 length, if the server is configured for 2 PCIe slots. If it is configured for 3 PCIe slots then all the slots are half height, half length.

This is a dual width, full height card that requires 2 six pin PCIe external power connections and a minimum 500W power supply. Dell says that there are 2 or 3 PCIe slots available depending on the original configuration with only one slot being full height, and 3/4 length, if the server is configured for 2 PCIe slots. If it is configured for 3 PCIe slots then all the slots are half height, half length.

I've done some googleing, but these external PCIe enclosures seem pretty pricey, at least in comparison to replacing the R620 with a 2u server that would accommodate the GTX980 internally. Wanting my cake and also, of course, to eat it.

Definitely doesn't have Thunderbolt, no. Surely such a thing could be added via a PCIe card... man this is getting out of control now. Perhaps I could whittle 2 inches off the length of a GTX980 card to wedge it in there? Sigh.

This server is actually doing nothing at the moment, and I am wondering if it can be re-purposed (since it's got tonnes of RAM) to handle a GPU-bound workload. Looks too hack-y to do what I was hoping, anyway, and it's likely better to spend the extra cash and get a whole new machine, rather than to try and shoe-horn an inexpensive video card into this older one.